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Diffstat (limited to 'clang/lib/Analysis/DeadStores.cpp')
| -rw-r--r-- | clang/lib/Analysis/DeadStores.cpp | 206 |
1 files changed, 0 insertions, 206 deletions
diff --git a/clang/lib/Analysis/DeadStores.cpp b/clang/lib/Analysis/DeadStores.cpp deleted file mode 100644 index f7523e5..0000000 --- a/clang/lib/Analysis/DeadStores.cpp +++ /dev/null @@ -1,206 +0,0 @@ -//==- DeadStores.cpp - Check for stores to dead variables --------*- C++ -*-==// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file defines a DeadStores, a flow-sensitive checker that looks for -// stores to variables that are no longer live. -// -//===----------------------------------------------------------------------===// - -#include "clang/Analysis/LocalCheckers.h" -#include "clang/Analysis/Analyses/LiveVariables.h" -#include "clang/Analysis/Visitors/CFGRecStmtVisitor.h" -#include "clang/Analysis/PathSensitive/BugReporter.h" -#include "clang/Analysis/PathSensitive/GRExprEngine.h" -#include "clang/Basic/Diagnostic.h" -#include "clang/AST/ASTContext.h" -#include "llvm/Support/Compiler.h" - -using namespace clang; - -namespace { - -class VISIBILITY_HIDDEN DeadStoreObs : public LiveVariables::ObserverTy { - ASTContext &Ctx; - Diagnostic &Diags; - DiagnosticClient &Client; -public: - DeadStoreObs(ASTContext &ctx, Diagnostic &diags, DiagnosticClient &client) - : Ctx(ctx), Diags(diags), Client(client) {} - - virtual ~DeadStoreObs() {} - - void CheckDeclRef(DeclRefExpr* DR, Expr* Val, - const LiveVariables::AnalysisDataTy& AD, - const LiveVariables::ValTy& Live) { - - if (VarDecl* VD = dyn_cast<VarDecl>(DR->getDecl())) - if (VD->hasLocalStorage() && !Live(VD, AD)) { - SourceRange R = Val->getSourceRange(); - Diags.Report(&Client, - Ctx.getFullLoc(DR->getSourceRange().getBegin()), - diag::warn_dead_store, 0, 0, &R, 1); - } - } - - virtual void ObserveStmt(Stmt* S, - const LiveVariables::AnalysisDataTy& AD, - const LiveVariables::ValTy& Live) { - - // Skip statements in macros. - if (S->getLocStart().isMacroID()) - return; - - if (BinaryOperator* B = dyn_cast<BinaryOperator>(S)) { - if (!B->isAssignmentOp()) return; // Skip non-assignments. - - if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(B->getLHS())) - CheckDeclRef(DR, B->getRHS(), AD, Live); - } - else if (UnaryOperator* U = dyn_cast<UnaryOperator>(S)) { - if (!U->isIncrementOp()) - return; - - Expr *Ex = U->getSubExpr()->IgnoreParenCasts(); - - if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(Ex)) - CheckDeclRef(DR, U, AD, Live); - } - else if (DeclStmt* DS = dyn_cast<DeclStmt>(S)) - // Iterate through the decls. Warn if any initializers are complex - // expressions that are not live (never used). - for (ScopedDecl* SD = DS->getDecl(); SD; SD = SD->getNextDeclarator()) { - - VarDecl* V = dyn_cast<VarDecl>(SD); - if (!V) continue; - - if (V->hasLocalStorage()) - if (Expr* E = V->getInit()) { - if (!Live(V, AD)) { - // Special case: check for initializations with constants. - // - // e.g. : int x = 0; - // - // If x is EVER assigned a new value later, don't issue - // a warning. This is because such initialization can be - // due to defensive programming. - if (!E->isConstantExpr(Ctx,NULL)) { - // Flag a warning. - SourceRange R = E->getSourceRange(); - Diags.Report(&Client, - Ctx.getFullLoc(V->getLocation()), - diag::warn_dead_store, 0, 0, &R, 1); - } - } - } - } - } -}; - -} // end anonymous namespace - -//===----------------------------------------------------------------------===// -// Driver function to invoke the Dead-Stores checker on a CFG. -//===----------------------------------------------------------------------===// - -void clang::CheckDeadStores(CFG& cfg, ASTContext &Ctx, Diagnostic &Diags) { - LiveVariables L(cfg); - L.runOnCFG(cfg); - DeadStoreObs A(Ctx, Diags, Diags.getClient()); - L.runOnAllBlocks(cfg, &A); -} - -//===----------------------------------------------------------------------===// -// BugReporter-based invocation of the Dead-Stores checker. -//===----------------------------------------------------------------------===// - -namespace { - -class VISIBILITY_HIDDEN DiagBugReport : public RangedBugReport { - std::list<std::string> Strs; - FullSourceLoc L; -public: - DiagBugReport(BugType& D, FullSourceLoc l) : - RangedBugReport(D, NULL), L(l) {} - - virtual ~DiagBugReport() {} - virtual FullSourceLoc getLocation(SourceManager&) { return L; } - - void addString(const std::string& s) { Strs.push_back(s); } - - typedef std::list<std::string>::const_iterator str_iterator; - str_iterator str_begin() const { return Strs.begin(); } - str_iterator str_end() const { return Strs.end(); } -}; - -class VISIBILITY_HIDDEN DiagCollector : public DiagnosticClient { - std::list<DiagBugReport> Reports; - BugType& D; -public: - DiagCollector(BugType& d) : D(d) {} - - virtual ~DiagCollector() {} - - virtual void HandleDiagnostic(Diagnostic &Diags, - Diagnostic::Level DiagLevel, - FullSourceLoc Pos, - diag::kind ID, - const std::string *Strs, - unsigned NumStrs, - const SourceRange *Ranges, - unsigned NumRanges) { - - // FIXME: Use a map from diag::kind to BugType, instead of having just - // one BugType. - - Reports.push_back(DiagBugReport(D, Pos)); - DiagBugReport& R = Reports.back(); - - for ( ; NumRanges ; --NumRanges, ++Ranges) - R.addRange(*Ranges); - - for ( ; NumStrs ; --NumStrs, ++Strs) - R.addString(*Strs); - } - - // Iterators. - - typedef std::list<DiagBugReport>::iterator iterator; - iterator begin() { return Reports.begin(); } - iterator end() { return Reports.end(); } -}; - -class VISIBILITY_HIDDEN DeadStoresChecker : public BugTypeCacheLocation { -public: - virtual const char* getName() const { - return "dead store"; - } - - virtual const char* getDescription() const { - return "Value stored to variable is never subsequently read."; - } - - virtual void EmitWarnings(BugReporter& BR) { - - // Run the dead store checker and collect the diagnostics. - DiagCollector C(*this); - DeadStoreObs A(BR.getContext(), BR.getDiagnostic(), C); - GRExprEngine& Eng = BR.getEngine(); - Eng.getLiveness().runOnAllBlocks(Eng.getCFG(), &A); - - // Emit the bug reports. - - for (DiagCollector::iterator I = C.begin(), E = C.end(); I != E; ++I) - BR.EmitWarning(*I); - } -}; -} // end anonymous namespace - -BugType* clang::MakeDeadStoresChecker() { - return new DeadStoresChecker(); -} |